A single lens camera comprises a lens and a camera body. The lens and the camera body are detachable and replaceable. In order to prevent the detachable lens from falling off and inaccurate positioning of electric circuit contacts, it is necessary to design a telescopic limiting structure that can extend and retract. A traditional solution of the telescopic limiting structure is to rotatably mount a lens on a camera assembling ring, use the assembling ring to hook the lens, and then insert a movable boss in the lens-release limiting structure into a lens groove, so as to achieve the purpose of preventing the lens from falling off due to free rotation in use.
However, the pressing method for a traditional lens-release press key block is performed along the axial direction of the lens, which should be no problem for ordinary cameras but is just neither convenient nor user-friendly, and is especially inconvenient for detaching the lens when the camera is applied to a mobile platform.